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<H1 class="no-header">curs_get_wch 3x 2025-02-15 ncurses 6.5 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>                 Library calls                <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>




</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
       <STRONG>get_wch</STRONG>,  <STRONG>wget_wch</STRONG>,  <STRONG>mvget_wch</STRONG>,  <STRONG>mvwget_wch</STRONG>,  <STRONG>unget_wch</STRONG>  - get (or push
       back) a wide character from <EM>curses</EM> terminal keyboard buffer


</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
       <STRONG>#include</STRONG> <STRONG>&lt;curses.h&gt;</STRONG>

       <STRONG>int</STRONG> <STRONG>get_wch(wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>
       <STRONG>int</STRONG> <STRONG>wget_wch(WINDOW</STRONG> <STRONG>*</STRONG> <EM>win</EM><STRONG>,</STRONG> <STRONG>wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>
       <STRONG>int</STRONG> <STRONG>mvget_wch(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>
       <STRONG>int</STRONG> <STRONG>mvwget_wch(WINDOW</STRONG> <STRONG>*</STRONG> <EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>

       <STRONG>int</STRONG> <STRONG>unget_wch(const</STRONG> <STRONG>wchar_t</STRONG> <EM>wc</EM><STRONG>);</STRONG>


</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>

</PRE><H3><a name="h3-Reading-Characters">Reading Characters</a></H3><PRE>
       <STRONG>wget_wch</STRONG> gathers a key event from the terminal keyboard associated with
       a  <EM>curses</EM>  window  <EM>win</EM>,  returning  <STRONG>OK</STRONG>  if  a  wide  character is read,
       <STRONG>KEY_CODE_YES</STRONG> if a function key is read, and <STRONG>ERR</STRONG>  if  no  key  event  is
       available.  <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG> describes the variants of this function.

       When  input  is pending, <STRONG>wget_wch</STRONG> stores an integer identifying the key
       event in  <EM>wch</EM>;  for  alphanumeric  and  punctuation  keys,  this  value
       corresponds to the character encoding used by the terminal.  Use of the
       control key as a modifier,  by  holding  it  down  while  pressing  and
       releasing  another key, often results in a distinct code.  The behavior
       of other keys depends on whether <EM>win</EM> is in keypad mode; see subsections
       "Keypad Mode" and "Predefined Key Codes" in <STRONG><A HREF="curs_getch.3x.html">getch(3x)</A></STRONG>.

       If  no input is pending, then if the no-delay flag is set in the window
       (see <STRONG><A HREF="nodelay.3x.html">nodelay(3x)</A></STRONG>), the function returns <STRONG>ERR</STRONG>;  otherwise,  <EM>curses</EM>  waits
       until  the  terminal  has  input.   If  <STRONG><A HREF="curs_inopts.3x.html">cbreak(3x)</A></STRONG>  or <STRONG><A HREF="curs_inopts.3x.html">raw(3x)</A></STRONG> has been
       called, this happens after one character is read.  If  <STRONG><A HREF="curs_inopts.3x.html">nocbreak(3x)</A></STRONG>  or
       <STRONG><A HREF="curs_inopts.3x.html">noraw(3x)</A></STRONG>  has  been  called,  it occurs when the next newline is read.
       (Because the terminal's canonical or "cooked"  mode  is  line-buffered,
       multiple  <STRONG>wget_wch</STRONG>  calls  may  then  be  necessary  to empty the input
       queue.)  If <STRONG><A HREF="curs_inopts.3x.html">halfdelay(3x)</A></STRONG> has been called, <EM>curses</EM> waits until input  is
       available or the specified delay elapses.

       If <STRONG><A HREF="curs_inopts.3x.html">echo(3x)</A></STRONG> has been called, and the window is not a pad, <EM>curses</EM> writes
       the wide character from the input queue to the window  (at  the  cursor
       position) per the following rules.

       <STRONG>o</STRONG>   If  the  wide character matches the terminal's erase character (see
           <STRONG><A HREF="curs_termattrs.3x.html">erasewchar(3x)</A></STRONG>), the cursor moves leftward one position and the new
           position is erased as if <STRONG><A HREF="curs_move.3x.html">wmove(3x)</A></STRONG> and then <STRONG><A HREF="curs_delch.3x.html">wdelch(3x)</A></STRONG> were called.
           When the window's keypad mode is enabled (see below), <STRONG>KEY_LEFT</STRONG>  and
           <STRONG>KEY_BACKSPACE</STRONG> are handled the same way.

       <STRONG>o</STRONG>   <EM>curses</EM>  writes  any  other  wide  character  to the window, as with
           <STRONG><A HREF="curs_add_wch.3x.html">wecho_wchar(3x)</A></STRONG>.

       <STRONG>o</STRONG>   If the window <EM>win</EM> has been moved or modified since the last call to
           <STRONG><A HREF="curs_refresh.3x.html">wrefresh(3x)</A></STRONG>, <EM>curses</EM> calls <STRONG>wrefresh</STRONG> on it.

       If  the wide character is a carriage return and <STRONG><A HREF="curs_inopts.3x.html">nl(3x)</A></STRONG> has been called,
       <STRONG>wget_wch</STRONG> stores the wide character code for line feed in <EM>wch</EM> instead.


</PRE><H3><a name="h3-Ungetting-Characters">Ungetting Characters</a></H3><PRE>
       <STRONG>unget_wch</STRONG> places <EM>wc</EM> into the input queue to be retrieved  by  the  next
       call  to  <STRONG>wget_wch</STRONG>.  A single input queue serves all windows associated
       with the screen.


</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
       <STRONG>wget_wch</STRONG> returns <STRONG>OK</STRONG> when it reads a wide character,  <STRONG>KEY_CODE_YES</STRONG>  when
       it reads a function key code, and <STRONG>ERR</STRONG> on failure.  <STRONG>wget_wch</STRONG> fails if

       <STRONG>o</STRONG>   its timeout expires without any data arriving, or

       <STRONG>o</STRONG>   execution  was  interrupted by a signal, in which case <EM>errno</EM> is set
           to <EM>EINTR</EM>.

       Functions taking a <EM>WINDOW</EM> pointer  argument  fail  if  <EM>win</EM>  is  a  null
       pointer.

       Functions  prefixed with "mv" first perform cursor movement and fail if
       the position (<EM>y</EM>, <EM>x</EM>) is outside the window boundaries.

       <STRONG>unget_wch</STRONG> returns <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> if there is no more room in the
       input queue.


</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
       See the "NOTES" section of <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>.

       All of these functions except <STRONG>wget_wch</STRONG> and <STRONG>unget_wch</STRONG> may be implemented
       as macros.

       Unlike <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>, <STRONG>wget_wch</STRONG> and its variants store  the  value  of  the
       input  character  in  an additional <EM>wch</EM> parameter instead of the return
       value.

       Unlike <STRONG>ungetch</STRONG>, <STRONG>unget_wch</STRONG> cannot distinguish function  key  codes  from
       conventional   character  codes.   An  application  can  overcome  this
       limitation by pushing function key codes with <STRONG>ungetch</STRONG> and  subsequently
       checking the return value of <STRONG>wget_wch</STRONG> for a match with <STRONG>KEY_CODE_YES</STRONG>.


</PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE>
       See the "EXTENSIONS" section of <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>.


</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
       Applications employing <EM>ncurses</EM> extensions should condition their use on
       the visibility of the <STRONG>NCURSES_VERSION</STRONG> preprocessor macro.

       X/Open Curses Issue 4 describes these functions.  It specifies no error
       conditions for them.

       See  the  "PORTABILITY" section of <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> regarding the interaction
       of <EM>wget</EM><STRONG>_</STRONG><EM>wch</EM> with signal handlers.


</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
       X/Open Curses Issue 4 (1995) initially specified these functions.   The
       System V  Interface  Definition  Version 4  of  the same year specified
       functions named <EM>wgetwch</EM> (with its variants) <EM>ungetwch</EM>.  These were later
       additions  to  SVr4.<EM>x</EM>,  not  appearing  in the first SVr4 (1989).  They
       differ from X/Open's later <EM>wget</EM><STRONG>_</STRONG><EM>wch</EM> and <EM>unget</EM><STRONG>_</STRONG><EM>wch</EM> in that <EM>wgetwch</EM> takes
       no  <EM>wch</EM>  argument,  but  returns the (wide) key code as an <EM>int</EM> (with no
       provision for distinguishing a  character  code  from  a  function  key
       code); and <EM>ungetwch</EM> takes a non-<EM>const</EM> <EM>int</EM> argument.


</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
       <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> describes comparable functions of the <EM>ncurses</EM> library in
       its non-wide-character configuration.

       <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>,    <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>,    <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>,     <STRONG><A HREF="curs_move.3x.html">curs_move(3x)</A></STRONG>,
       <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>



ncurses 6.5                       2025-02-15                  <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>
</PRE>
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<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
<ul>
<li><a href="#h3-Reading-Characters">Reading Characters</a></li>
<li><a href="#h3-Ungetting-Characters">Ungetting Characters</a></li>
</ul>
</li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-NOTES">NOTES</a></li>
<li><a href="#h2-EXTENSIONS">EXTENSIONS</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
<li><a href="#h2-HISTORY">HISTORY</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
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